Display apparatus

ABSTRACT

Provided is a display apparatus capable of reducing external light reflection to reduce an amount of glare of the outside, in which a translucent protection member is provided to cover an observation surface side of a display member including an organic EL light-emitting portion, in order to protect the display member. The display apparatus includes the display member with an organic EL light-emitting portion having a pair of electrodes and an organic compound layer provided between the pair of electrodes; and a casing for housing the display member, wherein a protection member is provided in the casing with a gap from the display member, and wherein a phase member and a polarizing member are formed on the protection member such that the polarizing member is located closer to a light extraction side than the phase member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display apparatus including anorganic electroluminescent (EL) light-emitting portion which has a pairof electrodes and an organic compound layer provided between the pair ofelectrodes.

2. Description of the Related Art

An organic EL device is attracting attention for a self light-emittingdisplay panel. The organic EL device includes a light-emitting layer foremitting light energy to each of an observation surface side and anon-observation surface side of a display panel. In order to effectivelyuse the light energy emitted to the non-observation surface side, ofelectrodes for injecting charges to the light-emitting layer, anelectrode located on the non-observation surface side is normallyprovided with a reflection function to reflect light emitted to thenon-observation surface side toward the observation surface side.Therefore, the light energy extracted from the observation surface sidecan be increased.

However, when the electrode located on the non-observation surface sideis provided with the reflection function to use as a reflectionelectrode, a phenomenon occurs in which light incident on the organic ELdevice from the outside is reflected on the reflection electrode andthen exits to the outside of the organic EL device again. In recentyears, a display panel including the organic EL device, which isincorporated in a digital still camera, a mobile telephone, or the likehas been used outdoors more often. When a reflection phenomenon iscaused by the reflection electrode, it is visually recognized as anexternal glare phenomenon at the time of actual use, and the phenomenonsignificantly deteriorates the image quality of the display panel. Thisis recognized as a problem specific to the display panel using theorganic EL device.

Japanese Patent Application Laid-Open No. H09-127885 discloses that aplurality of phase difference compensation films and a polarizing plateare combined as means for suppressing external light reflection, therebyreducing an amount of reflected light in a wide wavelength range.

Japanese Patent Application Laid-Open No. H10-068816 discloses acircular polarizing plate obtained by combining a ¼-phase differencecompensation film, a ½-phase difference compensation film, and a linearpolarizing plate.

As described above, a display member using the organic EL device (i.e.,organic EL light-emitting portion) is incorporated in a casing for adigital still camera, a digital video camera, or the like to be visuallyrecognizable. Therefore, a load such as a pressure or a shock from theoutside is easily applied to the display member. In addition, theorganic EL device is composed of a stacked thin film including anorganic compound layer. Therefore, the organic EL device is affected bythe pressure and shock from the outside, so that it is likely to cause abreak of a boundary of the organic compound layer or a short circuitbetween the electrodes by the loads, whereby the organic EL device isnot turned on with a possibility. Thus, in order to protect the displaymember, a translucent protection member is located so as to cover theobservation surface side of the display member.

However, in order to reduce the loads from the outside, the protectionmember is normally separated from the display member with a gaptherebetween. Therefore, light is reflected at an interface between eachof the members and the gap, with the result that it is likely toincrease the amount of glare by external light reflection at the time ofoutdoor use.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a display apparatuscapable of reducing external light reflection to reduce the amount ofglare of the outside, in which a translucent protection member isprovided so as to cover an observation surface side of a display memberincluding an organic EL light-emitting portion in order to protect thedisplay member.

In order to solve the above-mentioned problem, according to one aspectof the present invention, there is provided a display apparatusincluding: a display member including an organic EL light-emittingportion having a pair of electrodes and an organic compound layerprovided between the pair of electrodes, and a casing for housing thedisplay member, wherein a protection member is provided in the casingand is separated with a gap from the display member, and wherein a phasemember and a polarizing member are formed on the protection member suchthat the polarizing member is provided closer to a light extraction sidethan the phase member.

Further, according to another aspect of the present invention, there isprovided a display apparatus including: a display member including anorganic EL light-emitting portion having a pair of electrodes and anorganic compound layer provided between the pair of electrodes, and acasing for housing the display member, wherein a protection member isprovided on a light extraction side of the display member and separatedwith a gap from the display member, wherein a structure including theprotection member and the display member is provided in the casing,wherein a phase member and a polarizing member are formed on theprotection member such that the polarizing member is located closer to alight extraction side than the phase member.

According to the present invention, in order to protect the displaymember including the organic EL light-emitting portion, the phase memberand the polarizing member are formed on the translucent protectionmember separated with the gap from the display member so as to cover theobservation surface side of the display member. Therefore, light beamsreflected at an interface between the display member or the protectionmember and the gap and reflected on the electrode, which has areflection function, of the organic EL light-emitting portion includedin the display member are blocked by the phase member and the polarizingmember, whereby the amount of glare of the outside world can be reduced.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematic cross sectional views showing a protectionmember and a display member in an embodiment of the present invention,respectively.

FIG. 2 is a schematic view showing an example of a digital single-lensreflex camera as a display apparatus according to the embodiment of thepresent invention.

FIG. 3 is a schematic view showing an example of an EL display as thedisplay apparatus according to the embodiment of the present invention.

FIG. 4 is a schematic cross sectional view showing the display memberand the protection member which are located in a casing.

FIGS. 5A and 5B are schematic cross sectional views showing theprotection member as a modified example and the display member in theembodiment of the present invention, respectively.

FIG. 6 is an explanatory view showing a principle for reducing reflectedlight at the display member by the phase member and the polarizinglayer.

FIG. 7 is an explanatory view showing reflected light at an interfacebetween a gap and each layer adjacent to the gap.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments for embodying the present invention will bedescribed with reference to the attached drawings. However, the presentinvention is not limited to the embodiments of the present inventiondescribed below.

FIGS. 1A and 1B schematic cross sectional views showing a protectionmember and a display member in the embodiment of the present invention.In FIGS. 1A and 1B, reference numeral 1 denotes the protection member,21 a phase member, 22 a polarizing member, 23 a substrate, 24 reflectionelectrodes, 25, 26 and 27 organic compound layers, 28 transparentelectrodes, 29 a protection film, and 31 the display member.

The display member in this embodiment includes a plurality of organic ELlight-emitting portions formed on the substrate 23. In each of theorganic EL light-emitting portions, the organic compound layer 25, 26 or27 including at least a light-emitting layer is provided between thereflection electrode 24 and the transparent electrode 28 which areopposed to each other. An electrical connection is made such that one ofthe reflection electrode 24 and the transparent electrode 28 is acathode and the other thereof is an anode.

A hard substrate made of glass, silicon, stainless steel (SUS), or thelike, or a soft substrate made of plastic, epoxy, or the like can beused as the substrate 23. For example, a 1737 substrate produced byCorning Inc. is used as a glass substrate.

Thin film transistor (TFT) elements (not shown) and wiring structuresfor controlling the switching of the TFT elements are formed in matrixon the substrate 23. The reflection electrodes 24 having a reflectionfunction are formed over the TFT elements and the wiring structures andelectrically connected therewith. A metal material having a highreflectance such as Cr or Al can be used for the reflection electrodes24. In this case, for example, the metal material is deposited on thesubstrate 23 by a sputtering method, and patterning of the depositedmetal material is performed by a photolithography method, whereby thereflection electrodes 24 can be formed. A transparent electrode made ofindium tin oxide (ITO), indium zinc oxide (IZO), or the like may beformed on the deposited metal material to produce a stacked electrodestructure and use the stacked electrode structure as the reflectionelectrodes 24. A transparent layer obtained by depositing siliconoxynitride by a sputtering method may be provided between the metalmaterial and the transparent electrode, and the metal material and thetransparent electrode may be electrically connected with each otherthrough contact holes provided in the transparent layer to form thereflection electrodes 24.

The organic compound layers 25, 26 and 27 corresponding to respectivecolors of red (R), green (G) and blue (B) are formed on the reflectionelectrodes 24. It is only necessary that each of the organic compoundlayers 25, 26 and 27 has at least a light-emitting layer. Examples of alayer structure of the organic compound layer include a structure inwhich a hole transport layer, a light-emitting layer, and an electrontransport layer are stacked, or a structure in which a hole injectionlayer, a hole transport layer, a light-emitting layer, an electrontransport layer, and an electron injection layer are stacked. The layerstructure of the organic compound layers in the present invention is notlimited to these structures and thus other layer structures may beemployed.

The film thicknesses of the organic compound layers may be set todifferent film thicknesses for emitting respective colors according to adominant wavelength of emitted light. For example, the film thicknessmay be set such that an optical path length between a light emissionposition and the reflection electrode 24 may be set to a ¼ wavelength ora ¾ wavelength.

When a load such as a pressure or a shock is applied to the organic ELlight-emitting portion, in order to avoid the breaking of a boundary ofthe organic compound layer to prevent the organic EL light-emittingportion from being not turned on. In order to prevent such the case fromoccurring, it is preferable to stack a plurality of organic compoundlayers 25, 26 and 27 between the reflection electrode 24 and thetransparent electrode 28. Even in this case, it is preferable that adistance between the reflection electrode 24 and the transparentelectrode 28 in the organic EL light-emitting portion be set to 10 nm ormore and 1 μm or less.

In order to separate the organic compound layers 25, 26 and 27 from oneanother in a surface direction of the substrate 23, a pixel isolationfilm made of silicon nitride, a polyimide resin, a novolak resin, or thelike may be provided.

The transparent electrodes 28 are formed on the organic compound layers25, 26 and 27. Each of the transparent electrodes 28 is formed by, forexample, stacking films of ITO using a sputtering method. IZO (i.e.,compound of zinc oxide and indium oxide) may be used instead of ITO.

According to the above-mentioned structure, the plurality of organic ELlight-emitting portions are formed on the substrate 23. In each organicEL light-emitting portion, voltage is applied or current is allowed toflow between the reflection electrode 24 and transparent electrode 28through the TFT element formed in matrix on the substrate 23.

In order to prevent the characteristics of the organic EL light-emittingportions from deteriorating due to moisture, it is preferable that theentire display member be sealed with the protection film 29 so as tocover the plurality of organic EL light-emitting portions formed on thesubstrate 23. A silicon nitride film or a silicon oxynitride film may beused as a material for the protection film 29. Alternatively, a glasssubstrate may be bonded as the protection film 29 to the substrate 23.The protection film 29 is a member which is located over the substrate23 to prevent the plurality of organic EL light-emitting portions formedon the substrate 23 from being exposed to air, and is different from theprotection member 1 provided to be exposed from the casing as describedlater. Therefore, the protection film 29 is not necessarily provided inthe present invention.

The display member 31 is located in a casing 30 for housing the displaymember 31 and specifying the outline of a display apparatus to bevisually recognizable from the outside. In order to protect the displaymember 31, the translucent protection member 1 is separated with a gaptherebetween so as to cover an observation surface side (i. e., lightextraction surface side) of the display member 31 (see FIGS. 2 to 4).

The casing 30 described here corresponds to a casing for housing thedisplay member including the organic EL light-emitting portions andspecifying the outline of the display apparatus as in the case of animage pickup apparatus including an image pickup means, such as adigital still camera or a digital video camera, a mobile telephone, atelevision receiver, or the like. FIGS. 2 and 3 are schematic viewsshowing examples of the display apparatus according to this embodiment.FIG. 2 shows a rear surface of a digital single-lens reflex camera whichis the image pickup apparatus including the image pickup means. Theprotection member 1 is provided to be exposed from the casing 30 of thedigital single-lens reflex camera. FIG. 3 shows a front surface of an ELdisplay. The protection member 1 is provided so as to be exposed fromthe casing 30 of the EL display.

The protection member 1 is a translucent member and formed of, forexample, a transparent material. Glass, a polycarbonate material, anacrylic material, or the like can be used as a material of theprotection member 1.

The phase member 21 and the polarizing member 22 are formed on theprotection member 1. As shown in FIG. 4, the protection member 1described here is a member which is provided on the casing 30 in orderto protect the display member 31 located in an inner portion of thecasing 30 from a load such as a pressure or a shock from the outside.

An adhesive layer (not shown) may be provided between the protectionmember 1 and the phase member 21, and between the phase member 21 andthe polarizing member 22 to bond the respective members to one another,thereby stacking the members.

With respect to the arrangement among the protection member 1, the phasemember 21 and the polarizing member 22, the polarizing member 22, thephase member 21 and the protection member 1 are arranged in the statedorder from the light extraction side (i.e., observation surface side) inFIG. 1A. However, the present invention is not limited to such thearrangement. The protection member 1, the polarizing member 22 and thephase member 21 may be arranged in the stated order from the lightextraction side. Alternatively, the polarizing member 22, the protectionmember 1 and the phase member 21 may be arranged in the stated orderfrom the light extraction side. In other words, in any case, the phasemember 21 and the polarizing member 22 are formed such that thepolarizing member 22 is provided closer to the light extraction sidethan the phase member 21. When the protection member 1, the polarizingmember 22 and the phase member 21 are formed in the stated order fromthe light extraction side, an adhesive layer 32 may be provided betweenthe polarizing member 22 and the protection member 1 as shown in FIG.5A. In this case, when a refractive index of the adhesive layer 32 is anumerical value between a refractive index of the polarizing member 22and a refractive index of the protection member 1, external lightreflection can be further reduced.

A material of an adhesive layer 32 is not particularly limited. Apolyvinyl alcohol resin-based adhesive, an acrylic resin-based adhesive,a polyester resin-based adhesive, an urethane resin-based adhesive, apolyether resin-based adhesive, or a rubber-based adhesive may be used.

When the polarizing member 22 is to be located closest to the lightextraction side, it is preferable to use a material having nobirefringence as a material of the protection member 1. A surface of thepolarizing member 22 which is located closest to the light extractionside or a surface of the protection member 1 which is located closest tothe light extraction side may be subjected to antireflection processing.When the polarizing member 22 is located closest to the light extractionside, the influence of reflection caused at portions located between theprotection member 1 and the substrate 23 can be reduced.

A polycarbonate-based material, a norbornene-based material or the likecan be used as a material of the phase member 21. The phase member 21 ispreferably a film. It is preferable that the phase member 21 be a phasemember having at least a phase difference close to ¼ of 550 nm which isnear the peak of the relative spectral sensitivity curve of a human. Inthis case, it is preferable to set an optical axis angle between thephase member 21 and the polarizing member 22 to 45 degrees. In order tomaintain preferable phase compensation characteristics, the phase member21 may be composed of a plurality of stacked phase members as describedin Japanese Patent Application Laid-Open No. H10-068816. When theplurality of phase members are used, an optical axis angle between thepolarizing member 22 and each of the films composing the phase member 21is not necessarily limited to a numerical value of 45 degrees asdescribed above. Therefore, it is only necessary that each optical axisangle be set to an angle corresponding to a phase difference. Forexample, a phase member having a ½-phase difference and tilted at 15degrees relative to the polarizing member 22 may be provided under thepolarizing member 22. In addition, a phase member having a ¼-phasedifference and an optical axis tilted at 75 degrees relative to anoptical axis of the polarizing member 22 may be provided on the displaymember side (i.e., non-observation surface side) under the phase memberhaving the ½-phase difference. In this case, external light reflectionin a wider wavelength range can be reduced as compared with the casewhere only a single phase member is used.

As shown in FIG. 4, the protection member 1 is separated from thedisplay member 31 including the organic EL light-emitting portions witha predetermined gap therebetween. A gas or a vacuum may be present inthe gap. The gas present in the gap may be air, or the gap may be filledwith another gas. The another gas is an inert gas such as N₂ or Ar. Evenwhen a load is applied to the protection member 1 to elastically deformthe protection member 1, it is suitable that the gap between the displaymember 31 and the protection member 1 have a distance at which theprotection member 1 is not brought into contact with the display member31, that is, the distance is preferably 1 mm or more and 10 mm or less.

In FIG. 4, according to a method of locating the protection member 1 andthe display member 31, the protection member 1 and the display member 31are located in and on the casing 30 in which the display member 31 is tobe located, respectively. However, the present invention is not limitedto such the location. When the protection member 1 is provided on thedisplay member 31 and separated with a predetermined gap therefrom, astructure including the protection member 1 and the display member 31may be provided in or on the casing 30. In this case, when the displaymember 31 is directly provided in the casing 30, the protection member 1may be provided on the display member 31 to indirectly locate theprotection member 1 to the casing 30.

Next, an operation of the display apparatus according to this embodimentwill be described.

First, a principle for reducing the amount of reflected light in thedisplay apparatus by a phase member and a polarizing layer in acomparative example of the display apparatus according to the presentinvention will be described with reference to FIG. 6. For convenience ofexplanation with respect to light, FIG. 6 shows a state where there aregaps between a phase member 12 and a light-emitting layer 13, andbetween the light-emitting layer 13 and a reflection layer 14. However,actually gaps are absent and contact states are present.

The display member is composed of the reflection layer 14, thelight-emitting layer 13, the phase member 12, and a polarizing layer 11,all of which are stacked.

The polarizing layer 11 is a layer for transmitting only one of a p-waveand an s-wave of incident light. The phase member 12 includes aplurality of stacked phase difference films and has a phase differenceof a ¼ wavelength in a wide wavelength range. That is, a phase of thep-wave or the s-wave of light passing through the polarizing layer 11and the phase member 12 is shifted by a ¼ wavelength in a widewavelength range, so that the light is converted into circularlypolarized light.

Light 16 emitted from the light-emitting layer 13 toward the polarizinglayer 11 passes through the polarizing layer 11 and exits to the outsideof the display member. On the other hand, light 19 emitted toward thereflection layer 14 is reflected on the reflection layer 14. Thereflected light 15 passes through the light-emitting layer 13, the phasemember 12, and the polarizing layer 11 and exits to the outside of thedisplay member. As described above, both the light 16 and the light 19which are emitted from the light-emitting layer 13 exit to the outsideof the display member.

However, with respect to each of the light 16 and the light 19, only oneof linearly polarized components passes through the polarizing layer 11,so that light intensity reduces.

A part of incident light 17 from the outside of the display memberbecomes reflected light 0 on a surface of the polarizing layer 11. Ofthe incident light 17, light which is not reflected on the polarizinglayer 11 is converted into circularly polarized light by the polarizinglayer 11 and the phase member 12 to be reflected on the reflection layer14. When the incident light 17 is reflected on the reflection layer 14,a phase thereof is shifted by a half wavelength. Therefore, light 18passing through the phase member 12 cannot pass through the polarizinglayer 11.

According to the above-mentioned principle, reflected light of externallight reflected on the reflection layer 14 becomes only the reflectedlight 0 reflected on the surface of the polarizing layer 11. Therefore,the amount of reflected light can be reduced by only the display member.

However, as shown in FIGS. 2 and 4, for example, when the display memberis to be incorporated in the casing of the digital single-lens reflexcamera, in order to protect the display member, the translucentprotection member is provided and separated from the display member witha gap therebetween so as to cover the observation surface side of thedisplay member. In this embodiment, the gap between the protectionmember 1 and the display member is set to a distance of 1 mm or more and10 mm or less. That is, a user of the display apparatus according tothis embodiment observes the display member 31 located in the innerportion of the casing 30 through the translucent protection member 1. Asdescribed above, the protection member 1 is exposed to the outside andhas a function of preventing load such as a pressure or a shock from theoutside from being applied to the display member 31.

Depending on a use mode, in order to protect the surface of the displaymember 31, a protection film such as a polymer film, a passivation film,or a cover glass may be provided on the surface of the display member 31while being brought into contact with the display member 31. However,the above protection film is different from the protection member 1.

As described above, there is a gap between the protection member 1 andthe display member 31. Therefore, light is reflected at the interfacebetween each of the members and the gap, with the result that it islikely to increase the amount of glare by external light reflection atthe time of outdoor use.

Next, light reflected at an interface between a gap and a layer adjacentthereto will be described with reference to FIG. 7. In FIG. 7, the phasemember 21 and the polarizing member 22 are not formed on the protectionmember 1 unlike the case of the display apparatus according to thisembodiment. For convenience of explanation with respect to light, FIG. 7shows a state where there is a gap between the light-emitting layer 13and the reflection layer 14. However, a gap is absent and a contactstate is present.

In FIG. 7, the polarizing layer 11, the phase member 12, thelight-emitting layer 13 and the reflection layer 14 are formed toconstruct an integrated display member. The protection member 1 isprovided over the polarizing layer 11 and separated with a gaptherefrom. In such the structure, the light 17 incident on the displaymember from the outside is reflected on the surface of the polarizinglayer 11 and further reflected as light 2 on the surface of theprotection member 1. Therefore, when the protection member 1 isseparated from the polarizing layer 11 with a gap therebetween, thelight from the outside is reflected as the light 2 even on the surfaceof the protection member 1, so that it is likely to increase a glarephenomenon.

According to the display apparatus of this embodiment, in order toprotect the display member 31, the translucent protection member 1 isprovided with a gap therebetween so as to cover the light extractionside thereof. The phase member and the polarizing member are formed onthe protection member 1. Therefore, light beams reflected at theinterface between the display member 31 and the gap, at the interfacebetween the protection member 1 and the gap, and on the reflectionelectrodes 24 of the organic EL devices included in the display member31 are blocked by the phase member 21 and the polarizing member 22. As aresult, occurrence of the external glare phenomenon which is visuallyrecognizable at the time of use can be reduced to improve the displayquality of the display member 31.

Described above is the top-emission type display apparatus in which thelight emitted from the organic EL light-emitting portion is extractedfrom the side opposed to the substrate. According to the presentinvention, however, a bottom-emission type display apparatus may be usedin which the light emitted from the organic EL light-emitting portion isextracted from the substrate side.

Further, the TFT element is used to switch each of the organic ELlight-emitting portions. However, even when passive driving using simplematrix wirings is used, the same effect is obtained by the presentinvention.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2005-360026, filed Dec. 14, 2005, and Japanese Patent Application No.2006-274574, filed Oct. 6, 2006, which are hereby incorporated byreference herein in their entirety.

1. A display apparatus comprising: a display member including an organicEL light-emitting portion having a pair of electrodes and an organiccompound layer provided between the pair of electrodes, and a casing forhousing the display member, wherein a protection member is provided tothe casing and is separated with a gap from the display member, andwherein a phase member and a polarizing member are formed on theprotection member such that the polarizing member is located closer to alight extraction side than the phase member.
 2. A display apparatusaccording to claim 1, wherein the phase member and the polarizing memberare formed on the light extraction side of the protection member.
 3. Adisplay apparatus according to claim 1, wherein the phase member and thepolarizing member are formed on a side of the display member of theprotection member.
 4. A display apparatus according to claim 1, whereinthe polarizing member is formed on the light extraction side of theprotection member, and the phase member is formed on a side of thedisplay member of the protection member.
 5. A display apparatusaccording to claim 3, wherein the polarizing member is formed on theprotection member through an adhesive member, and the adhesive memberhas a refractive index of a value between a refractive index of thepolarizing member and a refractive index of the protection member.
 6. Adisplay apparatus according to claim 1, wherein the organic compoundlayer comprises a plurality of layers.
 7. A display apparatus accordingto claim 1, wherein the pair of electrodes are separated by a distanceof 10 nm or more and 1 μm or less.
 8. A display apparatus according toclaim 1, wherein the gap has a distance of 1 mm or more and 10 mm orless.
 9. A display apparatus comprising: a display member including anorganic EL light-emitting portion having a pair of electrodes and anorganic compound layer provided between the pair of electrodes, and acasing for housing the display member, wherein a protection member isprovided on a light extraction side of the display member and separatedwith a gap from the display member, wherein a structure including theprotection member and the display member is provided to the casing; andwherein the phase member and the polarizing member are formed on theprotection member such that the polarizing member is located closer to alight extraction side than the phase member.
 10. An image capturingapparatus comprising: a display member including an organic ELlight-emitting portion having a pair of electrodes and an organiccompound layer provided between the pair of electrodes, an imagecapturing means, and a casing for housing the display member and theimage capturing means, wherein a protection member is provided to thecasing and is separated with a gap from the display member, and whereina phase member and a polarizing member are formed on the protectionmember such that the polarizing member is located closer to a lightextraction side than the phase member.